Speed-change transmission, particularly for motor vehicles



March ,1963 HANS-JOACHIM M. FOERSTER 7 SPEED-CHANGE TRANSMISSION,PARTICULARLY FOR MOTOR VEHICLES Original Filed Dec. 8, 1951 2Sheets-Sheet 1 March 1963 HANS-JOACHIM M. FOERSTER 3,080,772

SPEED-CHANGE TRANSMISSION, PARTICULARLY FOR MOTOR VEHICLES OriginalFiled Dec. 8, 1951 2 Sheets-Sheet 2 dfiddfi iz Fatented Mar. 12, 39633,089,772 SPEED-CHANGE TRANSh il55i0hl, PARTECULARL FDR MOTGR VEHEQLESHans-Joachim M. Fiierster, fituttgart-llad Cannstatt, Germany, assignorto Daimler-hens Alitieugesellschaft, Stnttgart-Unterturlrheim, GermanyGriginal application Dec. 8, N51, Ser. No. 264?,668, now Patent No.2,892,355, dated .lane 30, 1959. Divided and this application Nov. it$958, Ser. No. 773,8tl6 31 Claims. (Cl. 7 1-485) The present applicationis a divisional application of the copending application Serial No.260,668 filed on December 8, 1951, entitled Speed-Change Transmission,Particularly for Motor Vehicles, now Patent No. 2,892,- 355.

The invention relates to a speed change transmission, particularly formotor vehicles, and more especially to a transmission of the typeincluding a hydrodynamic clutch incapable at very low speeds oftransferring any appreciable driving torque and, therefore, of stallingthe engine when the driven shaft is arrested, such as by stopping thevehicle.

It is the object of the present invention to provide a transmission ofthat type which excels by its simplicity and ruggedness and thus lendsitself to manufacture at a low cost and yet is reliable in operation.

Further objects of the invention will appear from a detailed descriptionof a number of embodiments shown in the accompanying drawings and thefeatures of novelty will be pointed out in the claims.

In the drawings, which illustrate more or less diagrammatically a numberof embodiments of the invention without, however, restricting theinvention thereto,

FIGURE 1 is a transmission including a hydrodynamic clutch and asecondary transmission shaft, said transmismission having four forwardspeeds;

FIGURE 2 is a diagram indicating the flow of power through thetransmission at different speed adjustments;

FIGURE 3 illustrates a transmission similar to that of FIGURE 1 for sixforward speeds;

FIGURE 4 is a diagram showing the flow of power through the transmissionwith diderent speed adjustments thereof;

FIGURE 5 illustrates another transmission for six speeds including asecondary transmission shaft and an epicyclic gearing;

FIGURE 6 is a diagrammatic cross section through the epicyclic gearingshown in FIGURE 5; and

FIGURE 7 is a partial axial section through a five speed transmissionincluding two epicyclic gearings arranged in tandem.

The transmission shown in FIGURE 1 comprises a driving shaft 3M that maybe the crankshaft of an automobile engine, a driven shaft 524 which maybe the shaft driving the rear axle transmission of the motor vehicle,and two motion-transmitting trains of elements, each of which connectsthe driving shaft 391 with the driven shaft 324 and which will bedescribed hereinafter. The first motion-transmitting train of elementsincludes a hydrodynamic clutch designated as a whole by 302 and composedof the driving section 303 rigidly connected with shaft SM and thedriven section ass. The driving section 3% is connected by adisengageable friction clutch 3% with the inner shaft 3% of a pair ofshafts 309 and 31% mounted in nested relationship. The driven section394; of the hydrodynamic clutch is connected by a friction clutch 354with the other shaft 310 of the pair of nested shafts. There is asecondary transmission shaft 316 spaced from the pair of shafts 309, 319and extending parallel thereto and suitably journalled in transversewalls of the transmission casing. The shaft 3l6is per:

manently geared to the hollow shaft 310 by a pair of meshing gears 314,315. Moreover, shaft 316 is permanently geared to the inner shaft 309 bya pair of meshing gears 355, 356. Also, the secondary transmission shaft316 carries a freely rotatable gear 318 engaging a gear 322 fixed to thedriven shaft 324 and is adapted by a multi-disk friction clutch 32b tobe clutched to gear 318. Another multi-disk friction clutch 357 isadapted to rigidly connect the two shafts 369 and 324 which are mountedin aligned relationship. If desired, gear 318 may be fixed to shaft 316and gear 322 may be freely rotatable on but adapted by a friction clutchto be clutched to shaft 324.

For setting the transmission to first gear the clutches 320 and 354 areengaged, whereas the clutches 3% and 357 are disengaged. Power istransmitted from the driving shaft 391 to the driven shaft 324 throughthe elements 393, 3494, 354, 3719, Std, 315, 316, 320, 3213, 322. Forshifting the transmission to second, the clutch 32% is disengaged andthe clutch 357 is engaged. Power is transmitted through the followingelements: 3M, 3%, 394, 354, 3M, 3E4, 315, 316, 356, 355, 357, 324. Forshifting the transmission to third gear, friction clutches 396 and 32hare engaged, While friction clutches 35 i and 357 are disengaged. Motionis transmitted via the elements 361, 3%, 306, 399, 355, 356, 316, 32%,318, 322, 324. For shifting the transmission to fourth gear, thefriction clutches 396 and 357 are engaged, while the friction clutches354 and 32% are disengaged. Power is transmitted via the elements 391,363, 306, 399, 357, 324. Additional gears not shown may be provided toafford a reverse transmission which may or may not include thehydrodynamic clutch.

From the foregoing description of the transmission shown in FIGURE 1 itwill appear that the first motiontransmitting train of elementsco-operatively connecting the driving shaft 301 with the driven shaft324 includes the hydrodynamic clutch MP2 and a first friction clutch354- which, when disengaged, will disable this motiontransmitting train.Moreover, it will appear that a second motion-transmitting trainconnecting the shafts 301 and 324 is established including the secondfriction clutch 306 (and excluding the hydrodynamic clutch) which, whendisengaged, will disable the second motion-transmitting train. The twosets of gears 355, 356 and 313, 322 may be optionally included in eithertrain. Thus, the set of gears 355, 356 will be operative in both thesecond gear and the third gear condition, the first of which onlyemploys the hydrodynamic clutch, while the set of gears 313, 322 willbecome operative in the first gear condition and in the third gearcondition, the first of which only employs the hydrodynamic clutch,Owing to the exclusion of the hydrodynamic clutch from the secondmotion-transmitting train, a higher efliciency of the transmission Willbe secured for the higher speeds.

Another embodiment of my invention is partly illustrated in FIGURES 3and 4 showing a transmission differing from that of FIGURE 2 by theprovision of an additional set of gears. The two nested shafts 499 and410 shown in FIGURE 3 are similar to shafts 3 09 and 310 in FIGURE 1 andare driven in the same manner as shown in FIGURE 1 by means of ahydrodynamic clutch 302 and two friction clutches$tl6 and 354 from adriving shaft 301. An illustration of such elements has been deemeddispensable in FIGURE 3, but it is to be clearly understood that suchelements are, in fact, combined with those shown in FIGURE 3.

When the transmission is set to the three lower gear conditions I to IIIindicated in FIGURE 4 at a, the motion-transmitting train of elementsincluding the hydrodynamic clutch is used, while the friction clutch 3%excluding the hydrodynamic clutch is engaged when the 3 transmission isshifted to fourth, fifth, or sixth gear, as indicated in FIGURE 4 at b.FIGURE 4 shows how the power is transmitted. in the first gear conditionclutch 420 only is engaged and in the second gear condition clutch 419only is engaged. In the third gear condition clutch 457 only is engaged,and in each of these three cases power is transmitted from. the hollowshaft 410 through a pair of meshing gears 414, 415 to the secondarytransmission shaft 416 and thence either through the pair of gears 418,422, or thepair of gears 417, 421, or through the pair of gears 455, 456and the clutch 457 to the driven shaft 424.

In the three upper gear conditions shown in FIGURE 4 at [1, power istransmitted through the inner shaft 409 and clutch 306 from the drivingshaft 301, the fourth gear providing for transfer of motion throughclutch 420, the fifth gear through clutch 419, and'the sixth gearthrough clutch 457. At 427 an additional gear is shown. forming part ofa set of reverse gears not shown in detail.

The shifting operation may be facilitated by the simultaneousdisengagement of clutches 306 and 354. That applies particularly to theoperation for shifting the trans mission into reverse. If desired, theclutches 320, 357, 420, 419, 457 may be constituted by toothed clutcheswhich may be provided with synchronizing means.

In FIGURES 5 and 6, I have illustrated embodiments of the presentinvention in which two gearings arranged in tandem are provided, onemarked A including a secondary transmission shaft 516 and the other onemarked B being an epicyclic gearing. The transmission shown in FIGURE 5comprises a hydrodynamic clutch designated by 502 as a whole andcomposed of a driving section 503 rigidly connected with the drivingshaft 501 of the transmission and a driven section 504 rigidly connectedwith one of a pair of shafts 509and 510 mounted in nested relationship,preferably with the outer one, 510 of the pair of shafts. The drivingsection 503 of the hydrodynamic clutch is connected by a friction clutch506, preferably comprising one pair of disks, with theinternal shaft509. If desired, a disengageable clutch may be interposed between thedriven section 504, of the hydrodynamic clutch and the associated hollowshaft-510. The latter is permanently geared to a secondary transmissionshaft 516 by a pair of meshing gears 514 and 515. A shaft 523 is mountedin the transmission casing in coaxial relationship to the shaft 509 andrigidly connected with the latter. The shaft 523 carries two gears 521and 522 keyed thereto. Gears 517 and 518 which mesh with the gears 521and 522, respectively, are freely rotatably mounted on and adapted to beclutched to transmission shaft 516 by means of friction clutches 519 and520, respectively, preferably of the multi-disk type.

The planetary gearing B comprises three coaxial relatively rotatableelements, to wit, a sun gear 558 freely rotatably mounted on shaft 523,a carrier 560 of planetary gears 559 rigidly connected with the drivenshaft 524, and an outer internal gear 561. The driven shaft 524 iscoaxially aligned with the shaft 523. The sun gear 558 is adapted to beeither connected with the shaft 523 by a suitable clutch, such as afriction clutch 562 of the multidisk type, or to be arrested by a brake563 mounted onthe transmission casing. A second brake 564 is mounted onthe transmission casing for the purpose of arresting the outer internalgear 561.

There is a second sun gear 565 fixed to the shaft 523 in permanent meshwith planetary gears 566 mounted on the carrier 560. The gears 566 areso long as to mesh at the same time with the planetary gears 559. Ifdesired, a clutch, such as a friction clutch, may be provided for thepurpose of connecting or disconnecting the gear 565 to and from theshaft 523.

This transmission has six forward speeds, the four lower ones beingtransferred via a hydrodynamic clutch, while. the two upper speeds aretransferred via the friction. clutch 506 by-passing the hydrodynamicclutch.

The transmission operates as follows:

First germ-The clutch 506 is disengaged; clutch 520 is engaged; clutch519 is disengaged; clutch 562 is disengaged; brake 563 is engaged; brake564 is disengaged. Power is transmitted via the elements 501, 503, 504,510, 514, 515, 516, 520, 518, 522, 523, 565, 566, 559, 560, 524; in thisoperation the epicyclic gearing B reduces the speed.

Second gear.--The clutch 519 remains disengaged and the clutch 520 isengaged; clutch 562 is engaged; brake 563 is disengaged. Owing to theengagement of clutch 562, the relatively rotatable elements of theepicyclic gearing are locked to one another and revolve in unison. Thepart A of the transmission acts in the same manner as in first gear.

Third gear.In part A of the transmission clutch 520 is disengaged andclutch 519 is engaged. Hence, motion is transmitted through thepair ofgears 517, 521 in lieu of the pair of gears 518, 522. In the epicyclicgearing B the operation is the same as in first gear, clutch 562 beingdisengaged and brake 563 being engaged.

Fourth gear.-The brake 563 is released; the clutch 562 is engaged. Theoperation in part A of the transmission 15 the same as in thirdgear,while the epicyclic gearing B is operated as in second gear, theelements thereof revolving in unison to provide for a direct con nectionof shafts 523 and 524.

Fifth gear.-The clutch 519 is disengaged; clutch 520 remains likewisedisengaged; friction clutch 506 is engaged. The epicyclic gearing Bremains set in the same manner as in the first gear condition and in thethird gear condition acting to reduce the speed. The hydrodynamic clutchis by-passed by friction clutch 506, the power being transmitted -via501, 503, 506, 509, 523, 565, 566, 560, 524.

' Sixth gear.-The part A of the transmission remains set as before,while the epicyclic gearing B is set in the same manner as for secondgear or fourth gear, thus eing locked as to revolve in unison. Power istransmitted directly from shaft 501 via the elements 506, 509 and 523 todriven shaft 524.

For the purpose of shifting the transmission to reverse, the clutch 562and the brake 563 are disengaged, while the brake 564 is engaged. Inthis event, the power is transmitted either through the hydrodynamicclutch 502 or through the friction clutch 506 to shaft 523 and thencevia gear 565, planetary gears 566, 559 and planetary gear carrier 560 tothe driven shaft 524.

If desired, gear 565 may be loosely mounted on shaft 523 and a clutchmay be provided for connecting the same.v As a result, the transmissionpermits of an additional forward speed by disconnecting gear 565,engaging clutch 562, releasing brake 563, and engaging brake 564.

The embodiment shown in FIGURE 7 differs from that shown in FIGURE 5 bythe provision of two epicyclic gearings C and D arranged in tandem.

The driving shaft 601, which may be the crankshaft clutch whichcooperates with a driven section 6020? said clutch, the latter beingencased in the cylindrical housing and adapted to be connected withshaft 610 forcommon rotation by a disengageable friction clutch 654.

Thus, it will appear that this embodiment differs from those describedsupra by the location of the driven sec tion of the hydrodynamic clutchadjacent to the engine' and of thedriving section remote from theengine.

Shaft 610 is surrounded by a hollow shaft 609 which is journalled in atransverse wall of the transmission casing;

by means of an anti-friction bearing and is adapted to beconnentedaviththe driying section 603-by means 01a] disengageable friction clutch 606.It will be noted that anti-friction rollers are interposed between thetwo shafts 609 and 616.

The shaft 610 is firmly connected or integral with a sun gear 668 of theepicyclic gearing C, whereas the outer internal gear 670 thereof isfirmly connected with the hollow shaft 609. Both gears mesh withplanetary gears 669-mounted on studs fixed to a carrier 671 formed by aflange of a shaft 672 mountedin coaxial relationship to shaft 610 andpreferably extending into an axial bore of the latter and journalled insuch bore by suitable antifriction rollers. The three elements 668, 670and 671 of the epicyclic gearing are thus mounted in coaxialrelationship for relative rotary motion.

The second epicyclic gearing D is formed by three similar relativelyrotatable elements, to wit, by a sun gear 675, by an outer internal gear673 and by a planetary gear carrier 676 carrying a plurality ofplanetary gears 674 which mesh with the gears 673 and 675.

The internal gear 673 is rigidly connected with the planetary gearcarrier 671, whereas the carrier of the planetary gears 674 is formedwith a hollow shaft 676 which surrounds the shaft 672 and extendsthrough the right hand end wall of the transmission casing, beingjournalled therein by a suitable anti-friction bearing. On the outsideof the latter the hollow shaft 676 carries a bevel gear 677 fixedthereto which is in mesh with a bevel 678 attached to a driven shaft 679journalled in a suitable bracket fixed to the transmission casing. Ifdesired, the driven shaft 679 may be mounted to extend parallel to theaxis of the transmission and may be geared to shaft 676 byspur gears.

Brakes 680 and 681 are attached to the transmission casing, the formerbeing adapted to arrest the internal gear 670 of the epicyclic gearing Cand the latterbeing adapted to arrest the sun gear 675 acting on asuitable drum which is connected with the sun gear 675 by a bushingjournalled on shaft 676. The shaft 672 extends the whole length of shaft676 through the-right hand end wall of the transmission casing and pastthe bevel gears and at its end carries a suitable drum fixed theretowhich cooperates with a brake indicated at 682, the latter beingsuitably fixed to a bracket bolted to the transmission casing. Thusbrake 682 when engaged will arrest shaft 672 and the carrier 671 ofgearing C and the internal gear 673 of gearing D. A clutch 684preferably a friction clutch of the multi-disk type, is mounted on abell integral with the 'end of'hollow shaft-676 and serves the purposeof optionally clutching the latter to the drum fixed to shaft 672. Inthis manner, the two shafts 672 and 676 may be connected for rotation inunison. Similarly, a clutch 683, which may be a friction clutch of themultidisk type, is interposed between an annular member fixed to theinternal gear 670 and the drum rigid with the sun gear 675 and adaptedto connect the elements 670 and 675 for common rotation.

The operation of the transmission illustrated in FIG- URE 7 is thefollowing:

For setting the transmission to first gear condition clutch 654 andbrakes 68 i) and 681 are engaged, whereas the other clutches and brakesare disengaged. Hence, the elements 676 and 675 will be arrested. Motionis transmitted via the following elements: 601, 603, 60 3, 654, 610,668, 669, 671, 673, 674, 676, 677, 678, 679. Both epicyclic gearings actas reduction gearings,

For settingthe transmission to second gear condition clutches 654 and684 and the brake 680 are engaged,

whereas the other clutches and brakes are'disengaged.

Thus, the internal gear670 is arrested, while the clutch 6S4 locks theelements of the epicyclic gearing 1) meme another for rotation inunison. Motion is transmitted via the hydrodynamic clutch and theelements 654, 610, 668, 669,671,672, 684, 676, 677 and 678 to the drivenshaft 679.

For setting the transmission to the third gear condition" 6 the clutches606 and 683 and the brake 682 are engaged,

while the other clutches and brakes are disengaged.

Hence, theinternal gear 673 and the planetary gear carrier 671 arearrested'by theshaft 672,, the drum attached thereto and the brake 6S2,whilethe epicyclic gearing C'is permitted to run idly. Motion .istransmitted via the elements 601, 603, 606, 609, 670, 683, 675, 674,676, 677, 678, 679.

In order to set the transmission forfourth gear the clutches 606 and 654and the brake 681 are engaged, while the other clutches and brakes aredisengaged. In this manner, the hydrodynamic clutch will cooperativelyconnect two of the three elements of gearing Cfor rotation substantially'in unison, both elements being capable of but such relative rotation aswill be permitted :by the slip in the hydrodynamic clutch. From theplanetary 'gear carrier 671 motion will be further transmitted throughthe elements 673, .674, 676, 677, 673 to the driven shaft 67 9.

For shifting the transmission to fifth gear the three clutches 606, 654and 683 are engaged, while'the fourth clutch and all of the brakesaredisengaged. .Here again the epicyclic gearing C is substantiallyblocked by the connection of two of its elements'through thehydrodynamic clutch. The-epicyclic gearing D .is likewise blocked byengagement of clutch 683. Therefore, allof the rotary .654 and-683-andthe brake 682 are engaged and'the other clutches and brakes aredisengaged. Hence, theinternal gear 670 of the epicyclic gearing C isconnected with the have provided a-transrnission of simple design=whichis capable of being-set upfor a pluralityof'different ratios oftransmission by the simple engagement or disengagement of frictionmeans, such as clutches and brakes.

While I have described a number of preferred .embodimentsof theinvention, 1 wish it to be:clearly understood that the same is innoway-limited tothe details of such' ernbodiments, but is capable ofnumerous modifications within the scope-ofthe appended claims.

'I claim:

1. A multi-speed transmission comprising input means,

output-means, a first-motion transmitting train.including :fiurdcoupling means, a'secOnd motion transmittingtrain including frictioncoupling means, at least two sets of meshing gear means providing atleast three forward speeds, each of said two sets of meshing gear meansincluding a planet carrier supporting'thereon a planet gear in meshingengagement with two coaxially arranged gears, the gears of one of saidsets being separate from the gears of the other gear set, meansincluding one set ofsaid gear means for optionally-connecting saidinput-means with said output means through one of said motiontransmitting trains in at least two'adjacenfforward speeds, and foroptionally connecting '-said-input.' means with said output meansexclusively through the other of said motiontransmitting trains in atleast-one other forward speed, and means for connecting said input meanswith said output means in another forward speed p roviding a-one-to-onetransmission ratio therebetween.

v '2. Ina transmission arranged for providing aplurality of forward.drive ratiosand a reverse drive ratio between a drive shaft and a drivenshaft, the combination of :an intermediate shaft, an additional i'shaft,:tfirst coupling means for transmitting torque from said drive shaft tosaid intermediate shaft, second coupling means for transmitting torquefrom said drive shaft to said additional shaft, a planetary gear sethaving a plurality of elements with a first one of said elementsconnected to said driven shaft and a second one of said elementsconnected to said additional shaft, third coupling means for connectinga third one of said gear set elements to said additional shaft, brakemeans for braking a fourth one of said gear set elements, and fourthcoupling means for connecting a fifth one of said gear set elements tosaid driven shaft, one of said forward drive ratios being completedthrough said second coupling means and said gear set by engagement ofsaid third coupling means and said brake means, and another of saidforward drive ratios being completed through said first coupling meansand said intermediate shaft by engagement of said first coupling meanswith said brake means disengaged.

3. In a transmission arranged for providing a plurality of forward driveratios and a reverse drive ratio between a drive shaft and a drivenshaft, the combination of an additional shaft, first coupling means fortransmitting torque from said drive shaft to said additional shaft, aplanetary gear set having a plurality of elements with a first one ofsaid elements connected to said driven shaft and a second one of saidelements connected to said additional shaft, second coupling means forconnecting a third one of said gear set elements to said additionalshaft, brake means for braking a fourth one on said gear set elements,and third coupling means for connecting a fifth one of said gear setelements to said driven means, one of said forward drive ratios beingcompleted through said first coupling means and said gear set byengagement of said second coupling means and said brake means, anotherof said forward drive ratios being completed through said first couplingmeans and said gear set by engagement of said second coupling means withsaid brake means disengaged, and said reverse drive ratio beingcompleted through said gear set by engagement of said brake means withone of said coupling means engaged and another of said coupling meansdisengaged.

4. In a transmission for providing a plurality of speed ratios between adrive shaft and a driven shaft, changespeed gear means including aplurality of gear elements connected between said drive shaft and saiddriven shaft, first shaft means connected with a first element of saidchange-speed gear means, first coupling means for transmitting torquebetween said drive shaft and said first shaft means in two consecutivespeed ratios of said transmission, second shaft means connected with asecond element of said change-speed gear means, second coupling meansindependently actuatable from said first coupling means for transmittingtorque between said drive shaft and said second shaft means in twoconsecutive speed ratios of said transmission, means including thirdcoupling means selectively operable to transmit torque between saidsecond shaft means and a third element of said change-speed gear means,and said driven shaft being connected to a fourth element of saidchangespeed gear means.

5. The combination according to claim 4, further comprising brake meansfor a fifth element of said changespeed gear means.

6. The combination according to claim 5, further comprising fourthcoupling means for selectively transmitting torque between said drivenshaft and one of said gear elements other than said second, third andfourth gear elements.

7. The combination according to claim 6, further comprising brake meansfor braking said third gear element.

8. In a transmission of the character described with at least fiveforward speeds, the combination comprising a driving shaft, a drivenshaft, a first motion-transmitting train of elements.oper-ativelyconnecting said driving shaft with said driven shaft and including ahydrodynamic clutch and a first friction clutch for selectivelydisabling said first motion-transmitting train upon disengagementthereof, a second motion-transmitting train operatively connecting saiddriving shaft with said driven shaft exclusive of said hydrodynamicclutch, but including a second friction clutch for selectively disablingsaid second motion-transmitting train upon disengagement thereof; saidfirst motion-transmitting train including meshing gear set meansproviding at least three speeds and said second traction-transmittingtrain including meshing gear set means providing at least two forwardspeeds, and means for selectively and consecutively actuating said firstmotion-transmitting train in at least two adjacent forward speeds orsaid second motion-transmitting train in at least two adjacent forwardspeeds different from said last-mentioned two forward speeds.

9. The combination claimed in claim 8 in which the gear set means ofsaid second motion-transmitting train form part of an epicyclictransmission, and wherei a third set of gears is included in said firstmotion-transmitting train of elements only.

10. In a transmission of the character described with at least fiveforward speeds, the combination comprising a driving shaft, a drivenshaft, a first motion-transmitting train of elements operativelyconnecting said driving shaft with said driven shaft and including ahydrodynamic clutch, first meshing gear set means pro viding ta leasttwo transmission speeds, and a first friction clutch for selectivelydisabling said motion-transmitting train upon disengagement thereof; asecond motion-transmitting train operatively connecting said drivingshaft with said driven shaft exclusive of said hydrodynamic clutch butincluding a second meshing gear set means providing at least threetransmission speeds and a second friction clutch for selectivelydisabling said second motion-transmitting train upon disengagementthereof; the transmission ratios of said first meshing gear set means inthe two transmission speeds thereof being lower than the transmissionratios of said second gear set means in the three transmission ratiosthereof, and means for optionally and consecutively engaging at firstsaid first motion transmitting train and each of the two transmissionratios thereof in two consecutive speeds and thereafter said secondmotion-transmitting train and each of the respective three transmissionratios thereof.

ll. The combination claimed in claim 10, in which at least one of saidtwo gear set means includes planetary gears.

12. A multi-speed planetary transmission having a plurality of forwardspeeds, comprising input means, output means, two planetary gear meanseach having a plurality of rotatable elements including two centralgears, at least one planet gear meshing with two respective centralgears and a planet carrier for a respective planet gear; firstengageable means operatively connecting one central gear of each of saidplanetary gear means with said input means in at least one of saidforward speeds; second engageable means including a hydrodynamic deviceoperatively connecting the other one of the two central gears of one ofsaid planetary gears with said input means in another one of saidforward speeds with said first engageable means engaged, and meansoperatively connecting said output means with at least one of therotatable elements of the other planetary gear means.

13. A multi-speed planetary transmission having a plurality of forwardspeeds according to claim 12, wherein said last-mentioned means isadapted to connect one rotatable element each of said two planetary gearmeans with said output means.

14. A multi-speed pianetary transmission having a plurality of forwardspeeds, comprising input means, output means, two planetary gear meanseach having a plurality of rotatable elements including two centralgears, at least one planet gear meshing with two respective centralgears, and a planet carrier for a respective planet gear; firstengageable means operatively connecting said input means with a firstone of the rotatable elements of one of said planetary gears, secondengageable means operatively connecting said input means with a secondone of the rotatable elements of said one planetary gear means, thirdengageable means operatively connecting said one rotatable element ofsaid one planetary gear means with one of the rotatable elements of theother planetary gear means, said output means being operativelyconnected with a second one of the rotatable elements of said otherplanetary gear means, and a third one of said rotatable elements of saidone planetary gear means being connected with a third one of therotatable elements of said other planetary gear means.

15. A multi-speed planetary transmission having a plurality of forwardspeeds according to claim 14, wherein said first and second mentionedrotatable elements of said one planetary gear means are the two centralgears thereof.

16. A multi-speed planetary transmission according to claim 15, whereinthe first and second-mentioned rotatable elements of said otherplanetary gear means are one of the two central gears thereof and theplanet carrier thereof.

17. A multi-speed planetary transmission having a plurality of forwardspeeds according to claim 16, wherein the third-mentioned rotatableelement of said one planetary gear means is the planet carrier thereofand wherein the third-mentioned rotatable element of said otherplanetary gear means is the other of the two central gears thereof.

18. A multi-speed planetary transmission having a plurality of forwardspeeds according to claim 17, further comprising fourth engageable meansfor selectively connecting said output means with both saidthird-mentioned rotatable elements of said one and other planetary gearmeans.

19. A multi-speed planetary transmission having a plurality of forwardspeeds according to claim 14, further comprising fourth engageable meansfor selectively connecting said output means with both thethird-mentioned rotatable elements of said one and other Planetary gearmeans.

20. A multi-speed planetary transmission having a plurality of forwardspeeds according to claim 19, further comprising brake means for atleast one of the three rotatable elements consisting of saidfirst-mentioned rotatable element of said one planetary gear means, saidfirst-mentioned rotatable element of said other planetary gear means,and said third-mentioned rotatable element of said one planetary gearmeans.

21. A mutli-speed planetary transmission having a pinrality of forwardspeeds according to claim 20, wherein at least two brake means areprovided for two of said three last-mentioned rotatable elements.

22. A multi-speed planetary transmission having a pinrality of forwardspeeds according to claim 21, wherein at least one brake means isprovided for each of said. three last-mentioned rotatable elements.

23. A multi-speed planetary transmission having a plurality of forwardspeeds according to claim 14, further comprising a hydrodynamic couplingin said second engageable means.

24. A multi-speed planetary transmission having a plurality of forwardspeeds according to claim 14, further comprising brake means for atleast one of the three rotatable elements consisting of saidfirst-mentioned rtatable element of said one planetary gear means, ofthe first-mentioned rotatable element of said other planetary gearmeans, and of the third-mentioned rotatable element of one of said twoplanetary gear means.

25. A multi-speed planetary transmission having a plurality of forwardspeeds, comprising input means, output means, two planetary gear meanseach having a plurality of rotatable elements including two centralgears, at least one planet gear meshing with two respective centralgears, and a planet carrier for a respective planet gear; firstengageable means operatively connecting said input means with one of thetwo central gears of one of said planetary gear means, second engageablemeans operatively connecting said input means with the other of the twocentral gears of said one planetary gear means, third engageable meansoperatively connecting said firstmentioned central gear of said oneplanetary gear means with one central gear of the other of saidplanetary gear means, said output means being connected with the planetcarrier of said other planetary gear means, and the other central gearof said other planetary gear means being operatively connected with theplanet carrier of said one planetary gear means.

26. A multi-speed planetary transmission having a plurality of forwardspeeds according to claim 25, further comprising fourth engageable meansselectively connecting said output means with said planet carrier ofsaid one planetary gear means.

27. A multi-speed planetary transmission having a plurality of forwardspeeds according to claim 26, further comprising brake means for atleast one of the three rotatable elements consisting of saidfirst-mentioned central gear of said one planetary gear means, of saidfirstmentioned central gear of said other planetary gear means, and ofsaid planet carrier of said one planetary gear means.

28. A multi-speed planetary transmission according to claim 27, whereinat least two brake means are provided for two of said last-mentionedthree rotatable elements.

29. A niulti-speed planetary transmission having a plurality of forwardspeeds according to claim 28, further comprising hydrodynamic couplingmeans intermediate said second engageable means and saidsecond-mentioned central gear of said one planetary gear means.

30. A multi-speed planetary transmission having a plurality of forwardspeeds according to claim 25, wherein said first-mentioned central gearof said one planetary gear means is a ring gear, said second-mentionedcentral gear of said one planetary gear means is a sun gear, and whereinsaid first-mentioned central gear of said other planetary gear means isa sun gear.

31. In a transmission of the character described, the combinationcomprising a driving shaft, a pair of shafts mounted in nestedrelationship, a first friction clutch for selectively connecting saiddriving shaft with one shaft of said pair of shafts, a hydrodynamicclutch and a second friction clutch operatively connecting said drivingshaft with the other shaft of said pair of shafts, an epicyclic gearhaving three relatively rotatable elements and including a planetcarrier for supporting thereon planetary gears, one of said elementsbeing connected with said one shaft of said first-mentioned pair ofshafts, another one of said elements being coimected with the othershaft of said first-mentioned pair of shafts, a driven shaft, gear meansfor gearing the third one of said elements to said driven shaft, meansfor optionally arresting one of said elements, and means for optionallyconnecting said elements for common rotation, said means for gearing thethird one of said elements to said driven shaft including a secondepicyclic gearing having three relatively rotatable elements andincluding a second carrier of planetary gears, a relatively stationarytransmission casing enclosing essentially completely the transmissionwith a part of said driving shaft and of said driven shaft extendinginwardly of said casing, a plurality of further nested shafts extendingoutwardly of said casing, two of said rotary elements of said secondepicyclic gearing being rigidly connected with respective ones of saidfurthe: nested shafts, and a brake and a clutch located outside of saidcasing for selectively arresting one of said 11 further nested shafts orconnecting the same to the other 2,312,849 one of said further nestedshafts. 2,353,905

2,454,014 References Cltefi m the file of th1s patent 2 518 824 UNITEDSTATES PATENTS 5 2 ,687,657 2,302,714 Pollard Nov. 24, 1942 12, Pollard-2 Mar. 2, 1943 Kelley July 18, 1944 Seybold Nov. 16, 1948 Simpson Aug.15, 1950 Kugel etal. Aug. 31, 1954

1. A MULTI-SPEED TRANSMISSION COMPRISING INPUT MEANS, OUTPUT MEANS, AFIRST MOTION TRANSMITTING TRAIN INCLUDING FLUID COUPLING MEANS, A SECONDMOTION TRANSMITTING TRAIN INCLUDING FRICTION COUPLING MEANS, AT LEASTTWO SETS OF MESHING GEAR MEANS PROVIDING AT LEAST THREE FORWARD SPEEDS,EACH OF SAID TWO SETS OF MESHING GEAR MEANS INCLUDING A PLANET CARRIERSUPPORTING THEREON A PLANET GEAR IN MESHING ENGAGEMENT WITH TWOCOAXIALLY ARRANGED GEARS, THE GEARS OF ONE OF SAID SETS BEING SEPARATEFROM THE GEARS OF THE OTHER GEAR SET, MEANS INCLUDING ONE SET OF SAIDGEAR MEANS FOR OPTIONALLY CONNECTING SAID INPUT MEANS WITH SAID OUTPUTMEANS THROUGH ONE OF SAID MOTION TRANSMITTING TRAINS IN AT LEAST TWOADJACENT FORWARD SPEEDS, AND FOR OPTIONALLY CONNECTING SAID INPUT MEANSWITH SAID OUTPUT MEANS EXCLUSIVELY THROUGH THE OTHER OF SAID MOTIONTRANSMITTING TRAINS IN AT LEAST ONE OTHER FORWARD SPEED, AND MEANS FORCONNECTING SAID INPUT MEANS WITH SAID OUTPUT MEANS IN ANOTHER FORWARDSPEED PROVIDING A ONE-TO-ONE TRANSMISSION RATIO THEREBETWEEN.